In one of the early years of the GBS someone put in an obs of 10600 YFHE. Clearly did not understand the “at any one time” rule. It did not get into the GBS
database as such. Years later, I think I put it in as 500. Even that is very high by GBS rules. Purely arbitrary figure of course. Both ideas of counts can be sensible or limited use, depending on whether you know the method.
From: Martin Butterfield [
Sent: Monday, 15 May, 2017 6:45 AM
To: COG List
Subject: [canberrabirds] YFHE eat your heart out
I was looked at the Global Big Day results (close to 6,000 species recorded) by big flock view and was astonished to see a record of 12,000 Blue Jays. Looking at
the checklist the observer reported counted and estimated as 1,000 birds every 20 minutes for 4 hours at a site on the Southern (US) shore of Lake Erie. The Sibley Field Guide comments that they
migrate in large flocks.
